Adjustable chair



; March 23, 1954- COLLURA 2,672,917

ADJUSTABLE CHAIR Filed May 19, 1950 7 Sheets-Sheet 1 INVENTOR. FRANCESCO COLLURA ATTORN Y March 23, 1954 COLLURA 2,672,917

ADJUSTABLE CHAIR RANCE$CO COLLURA ATTOKNE March 23, 1954 F. COLLURA 2,672,917

ADJUSTABLE CHAIR Filed May 19, 1950 7 Sheets-Sheet 3 III R\\ INVEN TOR. FRANCESCO COLLURA AT TOKNE March 23, 1954 COLLURA 2,672,917

ADJUSTABLE CHAIR Filed May 19, 1950 7 Sheets-Sheet 4 FRANCESCO COLLURA ATTORNEY March 23, 1954 CQLLURA 2,672,917

ADJUSTABLE CHAIR Filed May 19, 1950 '7 Sheets-Sheet 5 INVENTOR. 'FRANCESJLO COLLURA 'p/wr' fzm ATTORN 7 March 23, 1954 F, COLLURA 2,672,917

ADJUSTABLE CHAIR Filed May 19, 1950 7 Sheets-Sheet 6 as E 57 \IT 65 52. 66 e I 64- 0 I Q IN VEN TOR. FRANCESCO COL.L URA ATTORNE March 23, 1954 COLLURA 2,672,917

ADJUSTABLE CHAIR Filed May 19, 1950 7 Sheets-Sheet '7 III INVENTOR. FRANCESCO COLLURA ATTORNEY Patented Mar. 23, 1954 v American Optical Company,

Southbridge, 7

Mass, a voluntary association of Massachusetts Application May 19, 1950, Serial No. 162,951

1 This invention relates to improvements in chairs and has particular reference" to the provision of an adjustable chair such as is used in the practice of optometry and other arts where the'position of the individual or patient occupying the chair may be altered as desired. I

A principal object of this invention is to provide an adjustable chair permitting a patient occupying the chair to assume difi'eren't desired positions varying from an upright to an inclined position whereby most of said adjustments may be separately accomplished by operation of simple finger-tip controls and wherein a tilting movement may be imparted to the chair back, seat, apron and footrest simultaneously, and the said chair may be raised or lowered independent- 1y of the other adjustments as desired.

Another object is the provision of an adjustable chair of the above character wherein the various adjustments are performed hydraulically and automatically upon mani ulation of simple finger-tip control means.

Another object is the provision of a chair of the above character having" improved means for efficiently adjusting the chair back and backrest to the desired height and angle, independent means for adjusting the headrest for roper and comfortable support of the patients head, and means for quickly adjusting the footrest to accommodate for the difierences in the lengths of legs of various patients.

Another obect is to provide a chair of the above character with adjustable arms which may be slightly angled or completely lowered by operation of simple and efficient control means therefor.

A further object resides in the provision of a chair of the above character embodying mechanisms for simply and efficiently adjusting various portions of the chair to various positions and angles, such mechanisms being characterized by simplicity of structure, ruggedness, and ease of operation, the chair in its entirety being thoroughly reliable and ef icient in its operation, strong, durable, and comparatively inexpensive to manufacture; I

Other objects and advantages of the invention will become apparent from the following description taken-in connection with the accompanying drawings, in which:

Fig. 1 is a perspective view of an adjustable chair embodying the present invention;

Fig. 2 isa sectional view showing the operating mechanism located within the chair base;

Fig. 3 is a fragmentary side elevational view 9- Claims. (CL 155-25) 2 of the chair seat and back illustrating various positions to which they may be adjusted;

Fig. 45 is a fragmentary rear elevational view partly in section of the chair back illustrating the means for adjusting the same;

Fig. 5 is a sectional view taken on line 5-5 of Fig. 4 and looking in the direction of the arrows;

Fig. e is a sectional view taken on line 5-6 of Fig. 4;

Fig. '7 is a sectional view taken online 1-1 of Fig. 5 looking in the direction of the arrows;

Fig. 8 is a fragmentary sectional view showing the means for adjusting the chair arm-rests;

Fig; 9 is a fragmentary sectionalv'i ew taken on line 9-9 of Fig. 8 and looking in. the direction of the arrows;

Fig. 10 is a fragmentary sectional view taken on line ill-i0 of Fig. 8 and looking in the direction of the arrows;

Fig. 11 is a fragmentary side view of the adjustable foot rest;

Fig. 12 is a fragmentary sectional view through a portion of the chair base showing the manually operable foot pump for raising and lowering the chair; and.

Fig. 13 is a schematic diagram of the'hy'draulic system.

Prior art hydraulically operated chairs have consisted generally of a hydraulically actuated lift embodying a piston reciprocable in a cylinder and moved therein by the pressure of a hydraulic fluid. In such devices the fluid is drawn from a fluid chamber or reservoir and'pressures are built up on the fluid by means of a manually actuated pump usually operated by a hand. lever orafoot pedal. The result has been that inconvenient and time-consuming operations are necessary in adjusting the chair, and it is frequently necessary to make such adjustments several times before securing the proper desired position.

The present invention overcomes the above objections by providing a chair with automatically operating hydraulic means so constructed and arranged that by operation of simple finger-tip controls selected parts of the chair or combinations thereof may be adjusted to assume the desired position quickly, smoothly and effici'en'tly.

Referring to the drawings wherein like characters of reference designate like parts throughout the several views, the invention is embodiedin a chair having a base l3, a pedesta1l'4; seat portion i5 with attached apron It, foot rest [7 and arm rests i8 and rest 2!. The base I3 is formed as a disc like' portion 22 having an annular ring 23 disposed therearound and secured to the floor by means such as bolts inserted through openings 24 provided therefor.

The chair lifting mechanism is mounted on the base 22 and includes a supporting member 23 (Fig. 2) which is attached substantially centrally of the base 22 as by bolts 25 and is formed with a hollow upright portion 27. The outer surface of the upright portion 21 is threaded to receive the lower end of an inner sleeve 28, an outer sleeve 29 being slidably mounted over the inner sleeve 28 and having a plug 30 sealing its upper end.

A vertical rod 3| has one end fixedly located in the supporting member 26 within the upright 21 and carries at its other end a piston disc 32 which is adapted to snugly reside within a longitudinally reciprocable cylinder 33.

The cylinder 33 has its upper end closed as at 34 and has a portion 35 of smaller diameter inserted within the plug 33 and secured therein by a pin 36. A supporting bracket 31 is secured as v:by bolts to the plug 3% and carries the upper Portions of the chair, including the seat and back.

A hydraulic system is used to actuate the lifting mechanism and includes a pump 33 which is attached to and operable by an electric motor 39 carried by a bracket 40 attached to the outer sleeve 29. A conduit 4| has one end thereof in communication with the interior of the cylinder 33 above the piston disc 32 and has its other end in communication with a high pressure tank 42 (Fig. 13) containing a hydraulic fluid 43. A control valve 44, which may be suitably located for easy accessibility such as by attachment adjacent the seat of the chair (Fig. l), is suitably connected to the conduit 4-! for controlling th flow of hydraulic fluid to the cylinder 33 in a conventional manner.

A low pressure tank .5 is adapted to normally store some of the fluid 43, and upon operation of the pump 38 under control of the electric motor 39 fluid is transferred from tank 45 through conduits 45 and 41 to tank 42 where it is retained under high pressure. A safety device in the form of a relief valve 48 permits drainage of some of the fluid from tank 42 under excessive high pressure conditions, allowing it to pass to the tank 45 through a conduit 49 without passing through the pump 33.

Thus, when the operator turns the control valve 44 in one direction, fluid will be permitted to pass from the high pressure tank t2 into the interior of the cylinder 33 between the piston 32 and the end of the cylinder, the fluid pressure forcing the cylinder 33 upward and with it the outer sleeve 29, plug 36, bracket 37 and all'the chair parts attached thereto. To lower the chair, the control valve 44 is turned in the opposite direction whereupon the weight of the chair will force the fluid from the cylinder 33 back through conduit 4| to the valve 44 where it is made to flow into a bleeder lin or conduit 50 leading to the low pressure tank 45, thus relieving pressure upon the cylinder and permitting the chair parts to be lowered.

The outer sleeve 29 is rotatable about the inner sleeve 28 thus permitting the entire chair to be rotated on the base. The pedestal M is comprised of an inner skirt having its upper end connected to the chair seat portion and movable therewith, and an outer skirt 52 shaped to fit over the inner skirt 5|. The outer skirt is fixedly carried by the outer ends of brackets 53 (Fig. 2) connected .to a plate member 5 which is fitted over the upright 21 and rotatable thereabout. A machined track 55 is formed on the supportin member 26 to provide a satisfactory bearing surface upon which the plate member 54 is adapted to move and a retaining ring 53 is mounted in a circumferential groov in the upright 27 adjacent the upper surface of the plate member 54 to maintain the plate member 54 in proper relation to the supporting plate 26. The inner skirt 5|, being connected to the chair seat, is thus movable vertically therewith within the outer skirt 52.

Since it may be desired at times to use a manually operated lifting device for raising and lowering the chair to the desired position, there is also provided a pump 51 (Fig. 12) which is located within the pedestal M on a bracket 58 bolted or otherwise fixedly connected to the plate member 54. The pump 5'? carries a connecting member 59 which has a vertically disposed rod 50 connected thereto as by bolts 6!, the rod having its lower end slidably located within an opening in a lug 32 formed on the sleeve 29. The pump 57 carries a reciprooable plunger 63 having one end pivotally connected by a link (it to the short arm of a lever 65, the lever being pinned to a shaft 66 rotatably mounted in the bracket 53. The long arm of the lever 65 extends rearwardly and projects slightly through an opening in the pedestal I4 so that it may be manually operated. The pump 51 has conventional valve arrangements 68 and 69 associated therewith whereby the hydraulic fluid will be permitted to enter the chamber 81 through valve 38 and upon manual operation of the lever 65 will be forced through valve 63 into the conduit 4| (Fig. 2) to lift the chair in the same manner as with the electrically controlled pump.

The chair seat and back are supported upon a frame 10 (Fig. 2) which is attached by bolts 1! to a base 12, which base is provided with a pair of spaced attachment portions 13 which are connected by conventional means such as studs i5 for pivotal movement upon a pair of upwardly extending supporting arms 14 formed on the bracket 31 carried by the plug 30 of th chair lifting device. The frame N1 and base 12 through the pivotal connections with the arms 14 are adapted to revolve about the axes of the studs 15.

The base 12 is provided with a pair of spaced downwardly extending portions 76 adjacent one end which rotatably support the end of a shaft H. A piston rod it has one end pinned or otherwise fixedly secured to the shaft T! and has its other end carrying the usual piston is reciprocably positioned within a cylinder 80, which cylinder is pivotally connected by a bracket and pin connection 8| to the outer sleeve 29. A conduit 32 has one end in communication with the chamber in the cylinder at above the piston l9 and has it other end connected with the high pressure tank 42 through a control valve 83 (Fig. 13). Thus, to tilt the frame it the control valve 83 will be turned to allow hydraulic fluid to enter the cylinder from tank t2 and to force downwardly the piston 19 and with it the piston rod 18. This will cause the frame and its associated parts to swin about the pivot point 15. Upon turning the control valve as in the opposite direction, the Weight of the person occupying the chair will cause the frame it to return to its normal position, rotating about the pivot point '55 in the reverse direction to pull the piston rod 78 and piston 79 upwardly, thus expelling the fluid into the conduit 82 and subsequently phrase:

thr u h the. bleeder line 59 nto the low pressure tank 45.

The. cha r seat portion is pr vided with t usual ap ointments such as the pad 84 and side panels 85 for enclosing the working parts of the device.

The chair back 29 is attached to. and conSequently is movable. with the chair. seat I5. However, the back 29 may be adjusted independently oi the seat to provide proper support for the patient in various positions.

In Fig. 3 the chair seat and back are shown in various positions, the dot and dash lines indicating the back. only tilted, and the dotted outline indicatin both the seat and back inclined.

The chair back 20 includes a pair of box-like members 86 which are each pivot-ally connected by short shafts 81 (Figs. 2 and 8), to spaced lugs 88 formed on a rearwardly extending portion 89 of the seat base I2. A vertically extending side bar 90 i positioned for sliding movementin each member 89 and for pivotal movement about the axes of the shafts 81, upon operation of a hydraulic piston 9I (Figs. 2 and 13) The piston 9I comprises a cylinder 92 having an extension 93 formed on one end, which ex tension 93 is positioned within a depending boss 94 on the seat base It? and pinned or otherwise fixedly connected thereto. Within the cylinder 92 is the conventional piston disc 95 which is attached to and adapted to reciprocate upon movement of a piston rod 96 which carries on its outer rearwardly extending end a toothed rack 91. The rack 91 is operatively engaged by the teeth of a pinion 98 rotatably carried by a shaft 99 supported by the base 12, the rack 91 being held in engagement with the pinion 98 by means such as roller I00. Thus, upon operation of the piston 9|, the pinion 98 will be rotated about the axis of the shaft 99.

To the shaft 99 are pinned or otherwise fixedly attached the inner ends of a pair of spaced arms I01 which are rotatable with the shaft 99 and which are each respectively pivotally connected to the lower ends of the side bars 90. Thus, upon rotation of the pinion 9B and shaft 99 the lower ends of the side bars 90, which support th chair back, are drawn downwardly and inwardly as indicated by are line I02 in Figs. 2 and 3.

The piston 9I is operatively controlled by a,

valve I03 which can be turned to allow fluid 43 under high pressure to pass from the tank 42 (Fig. 13) through conduits M and I04 to the cylinder 92 where it will urge'the piston rod 99 inwardly to operate pinion 98 and thereby incline the chair back to the desired angle. When it is desired to return the back to normal position, the control valve I93 will be turned in the opposite direction whereupon fluid under high pressure will flow through conduit I04a into the cylinder 92 to urge the piston outwardly and the fluid previously forced into the cylinder will be released from high pressure and urged outwardly through conduits I94 and 59 to the low pressure tank 45. It is to be noted that when the fluid is forced through the conduits M and I94 to urge the piston rod 99 inwardly, the fluid in the cylinder rearwardly of the piston disc 95 will be forced outwardly through the conduits Ma. and 59 back to the low pressure tank 45.

The chair back is enclosed by front and rear panels I05 and I99 respectively (Figs. 5 and 6), the panels each being provided with longitudinal grooved portions adjacent each side thereof whereby they may he slid Vertically on the side upon manually bars .0. The. p nels are also provided'with spaced al gned inwardly projecting lugs I01 through which bolts are extended for maintaining tlfe panels in relative position for simultaneous sliding movement on the bars 90.

The front panel I05 is provided with a pair of spaced forwardly extending lugs I08, each carrying a short shaft I09 to which are pivotally connected rearwardly extending lugs IIO formed on a back rest III having suitably attached thereto a conventional pad I I2. The front panel I05 is provided with an integral inwardly extending bracket portion I I3 (Figs. 4 and 5) which has a vertical bore H9 in which is reciprocally positioned a shaft H5. The shaft IE5 carries at its lower end a toothed block 2 I6 which is adapted to engage the teeth of a rack II'l pivotally attached to and extending rearwardly of the back rest It I. A coiled tension spring H8 is provided over the shaft H5 within the bore 154 and is adapted to continually urge the block II6. downwardly to maintain it in desired engagement with the rack Iii. Conventional means may bev provided for maintaining the rack and block in con stant engagement with one another such as by providing a roller H9 having end portions carried by the respective front and rear panels. Tov lift the block H9 upwardly out of engagement with the rack ill, there is provided a handle I29 which extends through an opening in the. rear panel I96 and has its inner end pivotally. connected by a link IZI to a portion of the front panel I- The handle l29 is also pivoted at I22 to the upper end of the shaft H5. Thus, lifting handle I20, the shaft H5 will consequently be raised to lift the block II-fi out of engagement with the rack II'I, whereupon the back rest horizontal axis of shafts 09 to the desired inclined position. Then upon release of handle I29 the tension spring H9 will urge the block H9 downwardly into engagement with the rack Ill to retain the back rest in adjusted position.

Means also is provided for raising or lowering the back rest and comprises a pair of spaced vertically extending parallel members I23, the. upper ends of which are connected to the opposed ends of the pivot member I22. Between the lower ends of the parallel members I23 are. positioned a pair of spaced upwardly extending portions I26 of a yoke I25, the portions I26 being connected by a pin member me, which member has its end portions positioned in vertical slots I ZSa provided in each of the parallel members. L29. Thus, the members :23 can be moved as. a unit; in a vertical direction upon operation of handle I20 within the limits permitted by slots IZIia. The lower end of the yoke I29 is. provided with integral tabs or flanges lead which are adapted to be positioned beneath a transversely extending metallic leaf spring member I211. The yoke. I25 is adapted to rest upon the upper surface of the leaf spring I2! as shown best in- Fig. 5. The ends of the leaf spring l2! are adapted to engage the inner surfaces of the side bars. 99 to prevent the panels Hi5 and H39 together with the back rest Ill from lowering. However, when the handle are is operated todraw the shaft H5 upwardly, the parallel members I23. will consequently be simultaneously moved upwardly until the bottom ends of the slots I26a engage the pin member I29. Then, upon continued raising of the handle #99 the parallel members- I131 will lift the. yoke I25 caus-- III can be tilted about the ing the ends of the leaf spring I21 to engage the pins I2'Ia and I2") and flex, as shown in Fig. 4, whereupon the ends of the leaf spring will be disengaged from the side bars as per mitting the panels I05 and I06 and back rest I i I to be raised or lowered as desired. Then, upon releasing the handle I20, the leaf spring IE! will return the parts to their normal locked positions.

The chair arms I8 and I9 are each substantially U-shaped and have one leg portion provided with an upholstered pad or the like I28, while the opposed leg portion is adapted to extend through openings in the rear ends of the panels 85. An operating shaft I29 extending transversely beneath the chair seat has one end extending through an opening in one of the downwardly extending side portions it!) of a panel forming a part of the seat frame Iii, which end portion is threaded for reception of a handle I3I, a bushing I32 being provided over the shaft I29 and in engagement with the inner end of the handle I35. The other end of the bushing I32 engages a clamp I33 which is shaped to have a portion partially encircling the chair arm I8 and an end portion adapted to engage an inwardly turned lip IS l formed integral with the depending portion I'Sii of the frame it. The other end of the shaft I29 is attached as a bolt I 35 or the like to an end of a clamp 536 which similarly engages the chair arm 59 and a lip I34 formed on the opposed depe'-ding portion I30 of the frame. The frame ltl is also provided with downwardly extending bearing portions i3? which are grooved to form bearing surfaces for the arms I8 and III, as shown in Fig. 9. Upon rotating the handle I3I onto the shaft i255, pressure can be brought to bear upon the bushing I32 which will in turn exert pressure upon the upper end of the clamp Hi3 and simultaneously cause the upper end of the clamp 536 to be drawn toward clamp I 33, which action will cause the clamps to firmly engage the arms i8 and it and prevent them from moving. However, upon rotating the handle i3I in the opposite direction, pressure can be released upon the arms l8 and I9, whereupon they may be adjusted.

With the clamps released, the patient or chair operator can, upon grasping one or both of the arms I8 and I9, spread them to the extent permitted by a slot I38 formed in the side portion I30 (Fig. through which extends a stop button I39 carried by one arm of a lever I iil. The lever I46 is rotatably mounted over the chair arm I8 and is provided with an upwardly extending portion It! to which is pivotally connected a differential arm I 42. The portion of the lever I40 carrying the button I39 is provided with a central bore in which is slidably disposed a pin I43 having its outer end fixedly secured to the button I39 and having its inner end shaped to fit within an opening provided therefor in the arm I 8. The pin is further provided with an enlarged portion I43a which is adapted to be engaged by one end of a coil tension spring M l positioned within the bore over the pin Hi2. Thus, by manually pulling outwardly the button I39, the chair operator can cause the pin M3 to become disengaged from the arm It, permitting the arm to rotate independently of the arm It. The arm I9 is, however, provided with a push button device I45 similar to the push button I til, enabling it also to be independently moved.

However, in moving the arms only the slight extent necessary for many conditions, it is merely necessary, as described, to loosen the handle I3I which will release clamps I33 and I35 and permit the arm I8 to rotate to the extent Where the push button I39 will engage the bottom of the slot I38 preventing further lowering of the arm. Mechanism is provided, however, whereby the arm l9 will be simultaneously adjusted and comprises a toothed portion it formed on the end of the differential arm ItZ and in engagement with a pinion gear I41, and a toothed portion I48 of a second differential arm I t9 which is connected to a lever (not shown) carrying the push button I 55. Therefore, the arms I8 and It may be simultaneously adjusted slightly or may be independently permitted to swing downwardly, if desired.

The upper end of the chair back carries a head rest supporting member IEI to which the head rest device 2| is attached. The supporting member I'5I is provided with a pair of spaced upwardly extending lugs I52 (Figs. 1 and 5) which are connected by a fixed shaft 553. Rotatably mounted over the shaft E53 between. the lugs I52 is a bifurcated end portion I5 5 of a rearwardly extending supporting arm I55, the slot I55 between the bifurcations communicating with the bore in which the shaft IE3 is located. The supporting arm H55 is provided with a bifurcated outer end portion IEl similar to the portion I54 and having a supporting shaft I56 rotatably mounted therethrough, the slot H59 therein communicating with the bore in which the shaft I58 resides similarly to the slot lfiii. A pair of rearwarclly extending locking arms I63 are attached at one end to the outer bifurcation I 52 of the end portion I5? of the supporting arm I 55 by means such as a pin Ifil, extend longitudinally of the arm I55 through slots provided in the inner bifurcation Iiifa of the end portion I57 and have their inner ends connected by a stud H63. Between the inner ends of the locking arms I6!) is provided one end of a handle its, the handle being mounted over and rotatable with the stud I 53. Each end of the stud I63 is formed with extensions E65 which are off axis with respect to the major portion of the stud and have rotatably secured thereover the inner ends of a pair of longitudinally extending locking arms FEB. The forward ends of the arms R56 are attached to the outer bifurcation It? of the arm end portion I56 by means such as pin ltd, the arms Hi6 being slidable in grooves formed in the inner bifurcation H5705.

Upon rotation of the handle 4 64 about the axis of the stud I63, as indicated by numeral I69, the paired arms Itii and Edit can, due to the off axis connection, be moved toward and away from one another. When the handle I 6:3 is moved rearwardly about the axis Hit, the paired locking arms IEfi and Itiii are adapted to move so as to exert a pulling influence upon the bifurcated portions to which they are attached, causing said portions to become firmly clamped over the respective shafts 553 and ifiil, rendering them immovable.

The supporting shaft 558 has spaced lugs Ht of an upper supporting arm l'iI fixedly secured thereto for rotation therewith, the opposed ends of the upper supporting arm ill have head, rest pads I12 adjustably secured thereto in any conventional manner. Thus, it will be understood that upon moving handle it"? toward the forward end of the lower supporting arm I55, the pressure upon the shafts I53 and I 58 is relieved whereby the arms I55 and I'll can be adjusted,

as desired, to comfortably support a patients head, whereupon the handle I84 can be moved in the opposite direction to cause the shafts I53 and I58 to become firmly clamped in the manner described to retain the arms I55 and HI in adiusted position. It is important to note that the handle I54 is movable only in a direction parallel to the longitudinal axis of the supporting arm I55 and cannot be moved otherwise so as not to extend horizontally of the device where the clothing or person of the operator or patient can accidently come in contact with it.

The apron I 6 of the chair is provided with a downwardly extending supporting member M3 on each side thereof, and fixedly secured thereto as by screws I14. The rear edges of the members I13 are provided with a plurality of teeth I15 (Fig. 11) which are adapted to be engaged by teeth I16 formed on the curved ends of supporting side portions Ill, the side portions I11 being supported upon the forward edges of the depending members I13 by an integral cross member I18 connecting the portions I11. The footrest I1, of which the side portions I11 form a part, is provided with a suitable covering I19 and is adjustable vertically along the members I13 by tilting the outer end of the footrest I1 upwardly to disengage the teeth I16 from the teeth 15, whereupon the device can be adjusted upwardly or downwardly, as desired, and then, upon lowering the outer end thereof and permitting the teeth I15 and I16 to be engaged and the cross member I18 to engage the forward edges of the members I13, the device can be retained in adjusted position.

From the foregoing, it will be seen that there is provided an adjustable chair which can be quickly and easily raised or lowered upon operation of simple and efficient hydraulic controls, the individual parts of the chair being adjustable alone or in combination as described upon further operation of said hydraulic controls.

Although the novel features of the invention have been described and are pointed out in the annexed claims, it will be understood that many changes may be made in the construction and arrangement of parts shown and described without departing from the spirit of the invention as expressed in the accompanying claims. Therefore, it is to be understood that all matter set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having described my invention, I claim:

3.. A having in combination a supporting structure, a seat carried by said supporting structure, a back adjustably secured to said seat, said seat having guideway pivotally connected to its rearward end and back having a supporting member slidably positioned within said guideway for movement in the plane of the back and ap proximately normal to the axis of the pivotal connection of the guideway, said axis being substantially adjacent to and parallel with the intersection of the planes in which said seat and back lie, piston cylinder carried by said seat a piston rod reciprocable in said cylinder, a toothed rack carried by said piston rod, a gear wheel carried by said seat and operatively enwith said rack, and operating arm hav" ing one connected to the gear wheel for axial rotation therewith and having its opposed end pivotally connected to said supporting member at location below the axis of said guideway, the of the two connections of said operating arm being approximately parallel with the axis of the pivotal connection of the guideway, and hydraulic means for reciprocating said piston rod in said cylinder to permit said supporting member to be drawn downwardly within said guideway and simultaneously inclined about the pivotal connection of the guideway to the seat and the reverse comprising a supply tank containing hydraulic fluid under high pressure and operatively connected to said piston cylinder, a receiving tank connected to said. piston cylinder, and a control valve for controlling the flow of said hydraulic fluid whereby upon operation thereof said fluid will ilow under high pressure from said supply tank to one side of the piston in said cylinder to change the inclining of said back in one direction, and upon further operation of the control valve said fluid will flow from the piston cylinder to the receiving tank to change the inclining of said back in the reverse direction.

2. In an adjustable chair the combination of a base carrying supporting structure, a seat pivotally mounted on said structure, a back pivotally connected to said seat adjacent the rear thereof, and control means for automatically adjusting said back relative to said seat about said pivotal connection and the seat and back as a unit relative to the supporting structure including a supply tank carried by said supporting structure for fluid held under pressure, a receiving tank carried by said structure, and a control valve therebetween controlling the flow of fluid from the supply tank to the receiving tank, a piston' mounted on the base, a cylinder mounted thereover for reciprocal movement in a vertical direction and carrying said supporting structure having the seat pivotally mounted thereon, a second cylinder carried by the supporting structure, a piston reciprocally mounted in said second cylinder and operatively connected with said seat at a location spaced from its pivotal connection with the supporting structure, a third cylinder mounted on said seat, a piston reciprocally mounted therein and operatively connected with said back below its pivotal connection with the seat, and lead lines connecting each of said cylinders with said control valve whereby the adjustments of said back and'seat will be under the control of said control valve. 3. An adjustable chair of the character described for receiving a patient to be examined comprising a base, a seat and a back therefor, said base containing a first tank containing fluid under high pressure and a low pressure tank connected by a pair of conduits to form a complete circuit, means in the conduit leading to the high a pressure tank for maintaining pressure in said high pressure tank at a desired level, and valve means on the conduit leading from the high pressure tank for controlling the exit of fluid from said high pressure tank, a piston carried by said base, a cylinder movably mounted over the piston for vertical movement, a lead line from said valve means to said cylinder permitting the flow of fluid to raise the cylinder and lower it under the control of the valve means, said seat being pivotally mounted on said vertically movable cylinder for tilting movement about a horizontal axis located below the seat and in rearward oifset relation to the cylinder, a second cylinder carried by said first cylinder and connected with said valve means, a piston mounted for reciprocal movement in said cylinder and connected to the seat at a location spaced from its pivotal mount of the first cylinder for tilting of the seat and back as a unit about said axis under the control of said valve means, said back having depending portions slidably disposed in guideways mounted on the seat for pivotal movement about a second axis disposed approximately parallel to said horizontal axis about which the seat and back are tiltable as a unit and located adjacent the intersection of the planes in which said seat and back lie, and a third cylinder carried by said seat and connected by a pair of lead lines to said valve means and a piston reciprocally mounted in said cylinder for movement between the connection of said lead lines with the cylinder, said piston being connected with the lower end of the depending portions of said back at a location below said guideways to permit adjustment of said back under control of the valve means, said back having means for engaging the back and head of the patient seated in said chair.

4. In a chair, the combination of a base, a seat and relatively smooth functioning means for elevating or lowering said seat relative to the base with a minimum of annoyance to a patient seated on said chair comprising a piston having a cylinder reciprocally mounted over said piston, the piston being fixed over the base in upright posi tion and the cylinder supporting the seat, a receiving tank, a supply tank and a control valve mounted to move with said cylinder, a pair of conduits, one providing communication between the control valve and the supply tank and the other providing communication between the control valve and the receiving tank, means for delivering fluid from the receiving tank to the supply tank so as to maintain a constant predetermined pressure in said supply tank, a further conduit having one end communicating with the control valve and its other end with the interior of said cylinder, and control means located exteriorly on said seat for operating the control valve, said control valve being adjustable by said control means to open communication between the control valve and the conduit to one tank while closing communication with the conduit to the other tank whereby said control means function to cause fluid to flow into the cylinder under pressure when desired to elevate the chair and to exit from said cylinder when desired to lower the chair.

5. In a chair, the combination of a seat, supporting structure therefor, a back and means for adjusting said back relative to the seat comprising a slide carrying box pivotally attached to the rear of said seat for movement about an axis adjacent to and parallel with the intersection of the planes in which the seat and back are generally located, said back having a slide member vertically adjustable in said slide box with a free end located below said axis, a link having one end pivotally connected to said free end and its opposed end pivotally connected to the supporting structure at a location forwardly of the back and below the seat, the axes of the pivotal connections of said link at both said ends being substantially parallel with the axis of the pivotal connection of the slide box to the seat, and externally controlled means for swinging said link controlled amounts about its pivotal connection with the supporting structure whereby the back may be simultaneously tilted and lowered relative to the plane of the seat to accommodate the comfort of a patient seated in the chair.

6. In a chair, the combination of a seat, supporting structure therefor, a back and means for adjusting said back relative to the seat comprising a pair of slide carrying boxes pivotally attached to the rear of said seat adjacent its opposed sides for movement about an axis adjacent to and parallel with the intersection of the planes in which the seat and back are generally located, said back having a pair of slide members vertically adjustable in said slide boxes with a free end located below said axis,- a link having one end pivotally connected to said free end and its opposed end pivotally connected to the supporting structure at a location forwardly of the back and below the seat, the axes of the pivotal connections of said link at both said ends being substantially parallel with the axis of the pivotal connection of the slide boxes to the seat, and externally controlled hydraulic means for swinging said link controlled amounts about its pivotal connection with the supporting structure whereby the back may be simultaneously tilted and lowered relative to the plane of the seat to accommodate the comfort of a patient seated in the chair.

7. In a chair, the combination of a base, a seat adapted to be raised and lowered relative to the base and to be tilted relative thereto, a back pivotally mounted on the rear of said seat, and means for obtaining said adjustments in a smooth functioning manner with a minimum of discomfort and annoyance to a patient seated in the chair, said means including a piston fixed to the base, a cylinder reciprocally mounted over said piston for vertical adjustment and carrying supporting structure, the seat being mounted over said cylinder and pivotally connected to said supporting structure at a location below and rearwardly of the center of said seat, a second cylinder carried by the first cylinder adjacent its lower end and a piston reciprocally mounted therein operatively connected with said seat at a location spaced rearwardly from its pivotal connection with the supporting structure, a third cylinder having one end secured to the seat adjacent its forward side and a piston reciprocally mounted therein for adjustment toward and away from the rear of the seat and operatively connected with the lower portion thereof, a supply tank and a receiving tank carried by said supporting structure, means for driving fluid from the receiving tank to the supply tank to maintain a constant pressure therein, conduits from each of said tanks to a control valve, and conduits from said control valve to each of said cylinders, together with control means located on the exterior side of said seat for operating said control valve, said control valve 4 functioning under said control means to provide direct communication of the conduits, separately and plurally, with one of the tanks while cutting oif communication with the other to permit a relatively smooth adjustment of the seat and back to the convenience of the operator and comfort of the patient.

8. In a chair including a base, a seat and a back for said seat, means for obtaining relative adjustments of said chair elements in a smooth functioning manner with a minimum of discomfort and annoyance to a patient seated in the chair, said means including a piston fixed to the base, a cylinder reciprocally mounted over said piston for vertical adjustment and carrying supporting structure, the seat being mounted over said cylinder and pivotally connected to said supporting structure at a location below and rearwardly of the center of said seat, a second cylinder carried by the first cylinder adjacent its lower end and a piston reciprocally mounted therein operatively connected With said seat at a location spaced rearwardly from its pivotal connection with the supporting structure, a third cylinder having one end secured to the seat adjacent its forward side and a piston reciprocally mounted therein for adjustment toward and away from the rear of the seat and operatively connected with the lower portion thereof, a supply tank and a receiving tank carried by said supporting structure, means for driving iiuid from the receiving tank to the supply tank to maintain a constant pressure therein, conduits from each of said tanks to a control valve, and conduits from said control valve to each of said cylinders, together with control means located on the exterior side of said seat for operating said control valve, said control valve functioning under said control means to provide direct communication of the conduits, separately and plurally, with one of the tanks while cutting cfi communication with the other to permit a relatively smooth adjustment of the seat and back to the convenience of the operator and comfort of the patient.

9. In a chair, the combination of a seat and supporting structure therefor, said seat being pivotally connected to said supporting structure for tilting movement about an axis substantially parallel with the general plane in which the seat is arranged and which axis is located in rearwardly ofiset relation to the center of said seat and below said plane thereof, a cylinder secured to said supporting structure adjacent its lower part, and a piston reciprocally mounted therein and connected with a operating rod in turn pivotally connected to said seat at a location rearwardly of and below said axis of the pivotal connection of the seat to the supporting structure, together with means for forcing fluid under pressure into said cylinder on the side of the piston toward the pivotal connection of its operating rod with the seat to cause the seat to tilt rear- 14 wardly in accordance with the amount of movement of the piston, the location of said pivotal connections being such that the weight of a patient seated in the chair will cause the seat to slowly return to its normal position when said fluid is allowed to exit from the cylinder.

FRANCESCO COLLURA.

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